Loom linkage connector

ABSTRACT

The disclosure embraces a linkage for use in a textile weaving apparatus of the type employing a picker stick to position a yarn strand or strands in the course of a textile weaving operation. The picker stick is pivotally mounted at one end to move back and forth through an arc; intermediate the picker stick&#39;&#39;s ends, a strap is disposed thereabout to pull the stick through the arc and a spring member is employed to pull the stick through the same arc in the opposite direction; the strap&#39;&#39;s ends are secured to the base of a block of high density and high molecular weight polyethylene; in the end opposite its base, the block has a threaded bore into which is force screwed a threaded connector; the other end of the connector is pivotally attached to an actuating arm.

[ Nov. 27, 1973 United States Patent [191 Sherrill et al.

[ LOOM LINKAGE CONNECTOR Shapes, Cadillac Plastic & Chemical Co. Cover Pages,

Pages 8 and 12 relied on.

[76] Inventors: John B. Sherrill, Rt. 2; Paul E.

Bru chon, Rt. 4 Box 495; James T.

Primary ExaminerJames Kee Chi Att0rneyJohn W. Malley et al.

., Rt. 1 Box 551, Mount Holly, NC. 28120 Nov. 22, 1971 [22] Filed:

ABSTRACT 21 Appl. No.: 200,864

The disclosure embraces a linkage for use in a textile [52] US. Cl. 139/151 weaving apparatus of the type employing a picker stick to position a yarn strand or strands in the course of a textile weaving operation. The picker stick is piv- D03d 49/28, D03d 49/40 [58] Field of Search....................

[51] Int. Cl.

139/149, 152 otally mounted at one end to move back and forth through an arc; intermediate the picker sticks ends, a

References Cited UNITED STATES PATENTS strap is disposed thereabout to pull the stick through the arc and a spring member is employed to pull the stick through the same arc in the opposite direction;

the straps ends are secured to the base of a block of hi h densi Murray.......

g ty and high molecular weight polyethylene;

12/1964 Kenk.................. 139/15] 3/1953 Mastriani et FOREIGN PATENTS OR APPLICATIONS 139 151 in the end opposite its base, the block has a threaded bore into which is force screwed a threaded connector; the other end of the connector is pivotally attached to an actuating arm.

1,181,767 1/1959 France OTHER PUBLICATIONS Cadco I-IMW 1900, Properties and Uses Basic 1 Claim, 2 DrawingFigures 1 LOOM LINKAGE CONNECTOR BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION The present invention relates to an improved linkage arrangement for the picker stick of a textile loom, and, in particular to a connector constructed of high density, high molecular weight polyethlene having a threaded bore at one end into which the relatively coarser threaded shaft fo a steel ring connector is force screwed.

In present day, high-speed textile weaving operations, the need for constructing and installing loom apparatus that will operate over extended periods without breakdowns has long been recognized. As a result, attempts have been directed to either simplifying the repair or replacement of parts that have been susceptible to frequent failure due to wear or to employing expensively made parts so as to reduce the frequency of work stoppages caused by the failure of such parts.

The former of these attempts has not proved satisfactory since, while the repairs have been easily and quickly effected, the failure of certain elements of a loom still has resulted in fouling of the textile strands being woven thus resulting in damage to a portion of the textile stock. The latter approach, on the other hand, has met with limited acceptance and success for some elements of the conventional loom structure so that the the output efficiency of the looms has been increased enough to compensate for the increased cost of the machinery.

The present invention has for its chief object the provision of an improved connector for a textile weaving loom that will still further increase the efficiency of such apparatus by reducing work stoppages without requiring any significant investment or costly alteration of the conventional loom apparatus.

In the looms presently in use, picker sticks constructed from hard wood or like material are employed to throw a shuttle from a shuttle box through a warp shed to an oppositely disposed shuttle box equipped with its own picker stick to permit the shuttle to lay in a weft strand. In high speed looms it has been recognized that the elements that are subjected to the greatest wear are those that operate the picker sticks of the loom. The picker sticks, in general, are provided with mechanical linkages that are subjected to the most severe stresses since, in keeping with efficient manufacturing objectives, as the demand for increased output per unit of man-hours increases, the more rapidly must these linkages operate to reciprocate the picker sticks.

The prior art has endeavored to increase the operational life of the picker stick linkages by employing a relatively expensive cast aluminum connector for the link that functions to pull the picker stick through its are. One end of these aluminum connectors is attached to a picker stick by means of a strap and the other end is linked to a driven pivoting lever arm through a ring connector.

The foregoing connector arrangement has not met with success in overcoming the problem of picker stick linkage failure and, in particular, the aluminum casting has not been able to retain the threaded shank of the ring connector for any appreciable number of weaving runs despite the hardness of the casting. It can be appreciated that such failure is due chiefly to the severe shocks to which these linkage elements are repeatedly subjected upon reversal of the direction of movement of the picker sticks.

The present invention provides a greatly improved linkage connector that is substantially less susceptible to failure as compared to the connectors suggested in the prior art.

More specifically, it has been discovered that by utilizing a high density, high molecular weight polyethylene block in place of the cast aluminum connector, the picker stick mechanism can be operated for a substantially longer period than has previously been thought possible in this particular environment without loss of retention of the threaded shank of the ring connector.

In a preferred embodiment, it has been found that by forming in the polyethylene block a bore having a threaded surface that has a smaller spitch than the pitch of the threads on the shank ,of the ring connector and by forming the bore in the polyethylene block with a diameter that is slightly less than the exterior diameter of the threaded shank, a superior interengagement will be obtained between the shank of the ring connector and the block. This is due chiefly to the cold flow of the plastic about the threads of the shank resulting from the force screwing of the slightly oversized shank into the bore of the plastic material. In addition, the polyethylene of the type described above will exert a compressive force on the shank to aid in retaining the shank in the bore.

From the foregoing, it will be appreciated that a principal feature of the present invention resides in the provision of an improved linkage connector for loom picker sticks that will greatly reduce the incidence of failure in the picker stick manipulating mechanism and correspondingly increase the production efficiency of the loom. Another feature is the provision of an connector that is less costly to produce than the precision casted metal connectors presently in use and which is extremely easy to install.

The foregoing and other features and advantages of the present invention will become apparent in the more detailed discussion which follows, and in that discussion, reference will be made to the accompanying drawings as described below.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in perspective, with parts broken away, of the environment in which the article of the present invention is intended to be used; and

FIG. 2 is an exploded view in perspective of the connector block of the present invention and a ring connector having a threaded shank.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, there is illustrated in FIG. 1 a manipulating mechanism 10 for a picker stick 12 such as is conventionally used in modern high-speed textile looms. As previously noted, the picker sticks are disposed on opposite sides of a loom and are operated to cast a boat shuttle back and forth through the warp shed formed by the harness of the loom whereby a pick or weft strand will be laid in between the raised and lowered warp-end sections of the shed upon each shifting of these warp ends. Essentially, the picker sticks function as catapults as well as catchers of the boat shuttle. Since the picker stick linkages on each side of the loom are of identical construction as far as the present invention is concerned, only one will be illustrated and described.

As shown in FIG. 1, a picker stick 12 is in the position immediately before it is shifted to cast a shuttle from the shuttle box located adjacent its upper end (not shown) by being pulled toward shaft 16. Shaft 16 carries a bracket element 13 which is connected to shaft 16 and behind which is disposed an adjustable shaft stop 14. Shaft 16 is rotatably joumalled in a shaft box 18 which in turn is mounted on frame 20 by suitable means such as bolts 22 and 23. Conventional loom driving apparatus (not shown) are utilized to intermittently rotate shaft 16 so that the picker stick actuating arm 24 which is securely held in a bracket 26 will be rotated therewith. The lower end of the picker stick is securely mounted in a bracket consisting of side link members 28 and 30 by means of a washer plate 32 and a bolt and nut connection 34 which extends through a bore formed through the lower end of the picker stick 12 so as to securely clamp the lower end between the side links 28 and 30. The lower end of the side links 28 and 30 are formed integrally on the side opposite the washer plate 32 and a bore is provided therethrough for receiving a pin 36 about which the side links 28 and 30 as well as the picker stick 12 will pivot. The outer ends of the pin 36 are fixed in pitman link members 38 and 40 which in turn are rotatably mounted on a pin 42 which is carried in the base of a fixed member 44. The upper portion of member 44 carries a resilient bumper 46 which engages a crank link 48 which is pivotally mounted at one end on member 44 and also at its other end to side link 30. At the lowermost portion of side links 28 and 30 there is attached a strap member 50 which exerts a torque on the lower portion 52 of the side links 28 and 30 tending to rotate the side links 28 and 30 counterclockwise about pin 36 as viewed in FIG. 1. Strap 50 may be connected to a tension spring or wound on a spring wheel as at 54 in FIG. 1 which functions to wind the strap 50 thereabout.

The upper ends of the side links 28 and 30 are joined to form a strap support 58 which is provided with a stem 60 (shown in dotted lines) so that strap 56 may be wrapped around the stem 60 with portions of the strap extending on either side of the picker stick 12. A shim 62 is interposed between the stick l2 and the support 58.

The two ends of the strap 56 are secured to a connector block 64 at the base thereof by means of threaded bolts and nuts which are inserted through bores 66 formed through the base portion of the block 64. Preferably the interior surfaces of the ends of the strap 56 are placed directly in contact with the roughened surfaces as at 68 of the block 64 and washer plates 70 are interposed between the exterior sides of the strap and the nuts which are threaded onto the bolts, one of which is shown at 72 on plate 70 the other portion of which plate is broken away to illustrate the disposition of surface 68 of block 64.

Reference will now be made to FIG. 2 which illustrates a more detailed view of the block 64 as well as a ring connector 74 which is formed integrally with a threaded shaft 76. The block 64 is provided at its end opposite the bores 66 with a threaded bore 78 for receiving the threaded shank 76 of the ring connector. It has been found that by constructing the block 64 from high density, high molecular weight polyethylene and by machining the bore 78 with-threads that are relatively less coarse than the threads on the shank 76 and with the diameter of the bore 78 being slightly less than the diameter of the shank 76, the force screwing of the shank 76 into the bore 78 will effect a superior connection between these elements.

Preferably, the polyethylenes molecular weight is within the range of between 1.25 X 10 and 3.0 X 10 and has a correspondingly high density. The force screwing of the shank 76 into the bore 78 will assure an intimate interengagement between the threads of the shank 76 and the polyethylene material since the polyethylene material will exert a compressive force on the threads of the shank.

The ring connector 74 may be provided with a bearing member 80 which is formed with a pin receiving bore 82. With this arrangement, a steel pin 84 is used to connect the ring connector 74 to the actuating arm 24 through apertures located in the lowermost extremity of the actuating arm 24.

The enormous stresses to which the loom linkage elements are subjected can be appreciated by considering that in a conventional worsted loom, the shuttle must be cast back and forth through the warpshed by the picker sticks on the average of times per minute between the shuttle boxes which are manipulated by the picker sticks. Unexpectedly, the polyethylene block 64 has been found to perform substantially longer than a unitary metal linkage element between pin 84 and the bolts connecting the ends of the strap 56 as well as the previously noted cast aluminum connector.

While the connector of this invention has been shown and described in one form, it should be understood that this invention is capable of other forms falling within the scope of the appended claims.

We claim:

1. In a picker stick mounting arrangement of the type having a support frame, a bracket member pivotally connected to said support frame, a picker stick having one end thereof attached to said bracket member for pivotal movement therewith, means for pivotting said bracket member through a predetermined distance including a flexible strap connected to a portion of said bracket member, a linking element having one end attached to said strap and having a connecting means carried by its other end, means carried on said frame for intermittently imparting an impulse type pulling force to said connecting means whereby said bracket member and picker stick will be pivotted through said distance, the improvement comprising said element comprising a block of polyethylene having a molecular weight within the range of about 1.25 X l0 and 3.0 X 10 said connecting means including a member having a threaded rod portion of predetermined diameter, said block being formed with a bore of slightly less diameter than said rod portion, said bore being threaded along its length with threads that are undersized relative to the size of the threads on said rod portion, said rod portion being screwed into said bore with a force suchthat a compressive force is exerted by said polyethylene block on said rod portion and said polyethylene material intimately engages the threads of said rod portion. 1. 

1. In a picker stick mounting arrangement of the type having a support frame, a bracket member pivotally connected to said support frame, a picker stick having one end thereof attached to said bracket member for pivotal movement therewith, means for pivotting said bracket member through a predetermined distance including a flexible strap connected to a portion of said bracket member, a linking element having one end attached to said strap and having a connecting means carried by its other end, means carried on said frame for intermittently imparting an impulse type pulling force to said connecting means whereby said bracket member and picker stick will be pivotted through said distance, the improvement comprising said element comprising a block of polyethylene having a molecular weight within the range of about 1.25 X 105 and 3.0 X 105, said connecting means including a member having a threaded rod portion of predetermined diameter, said block being formed with a bore of slightly less diameter than said rod portion, said bore being threaded along its length with threads that are undersized relative to the size of the threads on said rod portion, said rod portion being screwed into said bore with a force such that a compressive force is exerted by said polyethylene block on said rod portion and said polyethylene material intimately engages the threads of said rod portion. 